Since you have tried your best, how about showing <b>what</b> you tried so we will know better how to help?

You are given vectors and and are asked to write x= <17, 13> in terms of the basis . What that means is find coefficents and so that . That gives you two equations to solve for and . Can you do that.

Thank you for your reply, I have solved the above problem. but the other question is unsolved. I do not know where to start. I think I should find the basis for the subspace and then do a orthogonal projection. but not sure how to find the basis. Please help, thanks.